Final answer:
The part of a neuron that may be covered with myelin is the axon. Myelin is provided by glial cells and significantly increases the speed of nerve impulse conduction. Axons in the CNS are myelinated by oligodendrocytes, while those in the PNS are myelinated by Schwann cells.
Step-by-step explanation:
In the context of neurons and their structures, the structure that may be covered with myelin is the axon. Myelin is a lipid-rich substance that insulates many axons, allowing electrical signals to be conducted more efficiently along the neuron. This insulation is provided by glial cells, with oligodendrocytes being responsible for myelinating axons in the central nervous system (CNS), and Schwann cells serving a similar function in the peripheral nervous system (PNS). As a result, the myelin sheath enhances the speed at which nerve impulses travel along the axon, which can be as long as a meter in human motor neurons from the spinal cord to the extremities.
The myelin sheath is periodically interrupted by gaps known as the nodes of Ranvier, which are essential for recharging the signal as it travels down the axon. It is important to note that while the axon is surrounded by this myelin sheath, the dendrites and cell body remain unmyelinated. Dendrites are responsible for receiving electrical signals, and the cell body, containing the neuron's nucleus and organelles, integrates these signals before they are transmitted down the axon.